Title of Invention	A DEVICE FOR IMPROVED MANUAL GROUTING OF ROOF BOLTS IN MINES
Abstract	In the present invention there is provided a device for improved manual grouting of roof bolts in mines, which enables putting only water soaked grouting cement inside a drilled hole in the roof of the mine keeping aside poly-bag of the cement capsules during manual roof bolting operation. The cement containing polybag creates problem of not only covering the bolt to be grouted but also creates voids responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency. The invented device consists of an openable cylindrical pipe made up of two symmetrical semi-circular parts having diamond cut knurling in the concave inner surface, an annular ring having circumferential sharp teeth and a piston having long piston rod, and a lock pin for tightly locking the two longitudinal hinged halves of the cylindrical pipe. This enables to withhold the polybag of the cement capsule which is responsible for non-homogeneous filling of the annular space system and thus decreasing grouting efficiency.

Title of Invention

A DEVICE FOR IMPROVED MANUAL GROUTING OF ROOF BOLTS IN MINES

Abstract

In the present invention there is provided a device for improved manual grouting of roof bolts in mines, which enables putting only water soaked grouting cement inside a drilled hole in the roof of the mine keeping aside poly-bag of the cement capsules during manual roof bolting operation. The cement containing polybag creates problem of not only covering the bolt to be grouted but also creates voids responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency. The invented device consists of an openable cylindrical pipe made up of two symmetrical semi-circular parts having diamond cut knurling in the concave inner surface, an annular ring having circumferential sharp teeth and a piston having long piston rod, and a lock pin for tightly locking the two longitudinal hinged halves of the cylindrical pipe. This enables to withhold the polybag of the cement capsule which is responsible for non-homogeneous filling of the annular space system and thus decreasing grouting efficiency.

Full Text	The present invention relates to a device for improved manual grouting of roof bolts in mines. The present invention particularly relates to a device for putting only water soaked grouting cement inside a drilled hole in the roof of the mine, withholding the poly-bag of the cement capsules during manual roof bolting operation. The present invention more particularly relates to a device which allows the grouting cement to be pushed into a drilled roof hole and withholds the cement containing polybag which creates problem of not only covering the bolt to be grouted but also creates voids responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency. Roof bolting as a system of mine support is practiced in most of the coalfields in India. In most of the mines roof bolting is carried out manually using cement capsule cartridge. In the present hitherto known roof bolting system cement capsules followed by a roof bolt is inserted into a predetermined hole made by drilling machine in the mine roof. In the common practice for manual roof bolting, first of all hole is made in the mine roof using a drilling machine. Then water soaked cement capsule packed in perforated polybag is pushed in series into the hole with the help of a push rod, such as a wooden ranging rod. A tor steel roof bolt is inserted immediately thereafter into the hole, which punctures the cement packed polybag and thus fills the annular space between bolt and drilled hole with the cement along the full column. After the bolt is pushed into the hole, to make homogeneous filling of cement in annular space, the bolt is rotated to churn the cement and also to tear off the polybag of the cement capsules cartridge and thereby cement fills the annular space between the bolt and hole. But the cement containing polybag creates problem of not only covering the bolt but also creates voids which are responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency. It has been observed that plastic often wraps up over the bolt during churning operation and thus prevents proper bondage between the bolt and the cement grout. This decreases the efficiency of the roof bolting by improper load transformation from the surrounding rock to the bolt through cement grout. To overcome this difficulty roof bolting machine with separate pump was used for grouting the bolt by pumping cement slurry into the hole. But this method has inherent drawbacks, as follows: a) Costly pump. b) Wastage of cement slurry. c) Improper time management. d) Complicated operation. e) Requirement of skilled worker. On making a search of patent databases the following patent references come to light. References may be made to US Patent No. 4126003, titled: Inorganic cement grouting system for use in anchoring a bolt in a hole; US Patent no.4126005, titled: Inorganic cement grouting system for use in anchoring a bolt in a hole and compartmented package for use therewith and US Patent no.4126009, titled: Inorganic cement grouting system for use in anchoring a bolt in a hole, wherein is disclosed an apparatus and a method in which two separate components of an inorganic cement grouting cement are mixed and delivered into the hole separately i.e. from separate feeding conduits or more preferably in separate compartment of a frangible package which is broken by the penetration and rotation of the reinforcing member. Reference may also be made to US Patent no. 411638, titled: Clog-free inorganic grout emplacement gun wherein is disclosed an apparatus in which a emplacement gun particularly adopted for use in coal or similar mines for retaining roof bolts in bore holes. Four numbers of separate paths have been made into the hole for conveying the different mixing materials. Reference may be drawn to US Patent no. 4079592, titled : Method of and apparatus for feeding and inserting bolts in a mine roof wherein is disclosed an apparatus and a method about installing resin anchored roof bolts in mine roof with the help of mobile roof bolter frame. In an apparatus for installing resin anchored roof bolts in a mine roof, continuous bolt material is stored on a spool rotatably mounted on a mobile roof bolter frame. As the apparatus advances along the mine passageway, the bolt material is uncoiled from the spool and guided upwardly into spaced apart, resin filled holes that are preformed in the mine roof. The bolt material is severed just beneath the roof at each hole to form a unitary roof bolt. A stop is formed in the unitary bolt with a hydraulically operated head and mandrel mechanism that makes a right angle bend in the bolt just beneath the mine roof. Reference may be taken from the US Patent no. 4643619, titled : Apparatus for feeding cement material into a drill hole for cement bolting of a rock, wherein is disclosed an apparatus and a method of feeding cement into a drill hole for cement bolting of a rock in which a feeder pipe is pushed into the hole portion to be filled with cements. Cement is fed into the hole beginning from the bottom of the hole portion and the pipe is displaced outward in the hole when the cement fills the hole. Finally, feeding of cement stopped and the pipe is removed and then rock bolt is pushed into the pipe. Reference may also be taken from the US Patent no.6793445, titled : Method and apparatus for insertion of rock bolts wherein is disclosed an internal cavity into the rock bolt having an injection assembly to retain the grouting compound. When the rock bolt is inserted in the member and when the injection assembly engages the member the passage is in communication with the internal cavity in the rock bolt. Whereupon the injection assembly operates to inject a predetermined quantity of the grouting compound into a bolt hole in the rock strata via the internal cavity of the bolt. Reference may also be drawn from the US Patent no.6033153, titled : Rock bolt and method of installing a rock bolt wherein is disclosed an apparatus and a method of installing a rock bolt .particularly a hollow bolt. The method of installation utilizes a chemical anchor in form of a cartridge. Reference may also be made to US Patent no.5494380, titled : Resin injector system, wherein is disclosed an apparatus and a method which employs gas to position a resin sausage into a bolt hole drilled by a rock bolter. The invention relates to a system and a method which employs gas to position a resin sausage into a bolt hole drilled by a rock bolter. The system provides a controlled quantity of liquid into a resin sausage insertion chamber prior to supplying the gas to eject the sausage from the resin sausage insertion chamber. The liquid enhances the reliability and accuracy of the placement of the sausages in the bolt hole. Preferably, the system includes an expansion chamber through which the gas passes. The expansion chamber is provided so that the gas can be partially displaced by liquid and thereafter, liquid will be advanced into the resin sausage insertion chamber prior to the gas. The system can either have its own fluid supply or alternatively use a fluid supply of the rock bolter if one is provided for flushing the bolt holes. In either case, it is preferred that the expansion chamber is adjustable so as to allow the volume of liquid and gas to be adjusted for the operating conditions of the rock bolter. From the above, it is observed that in the hitherto known prior art there are various types of methods and devices available which use separate conduit pipes, feeders pipes and in some cases internal cavity was made in the rock bolts itself to send the inorganic cement slurry. In some device resins and other chemicals were used for anchoring. From the hitherto known prior art it is also seen that none have disclosed any method or device about the manual grouting of roof bolts in mines using cement capsuling i.e cement packed in polybag in form of capsule and the problems of anchoring thereof. From the hitherto known prior art it is obvious that the devices and methods which are mentioned herein above are costly as well as complicated in design and may not be suitable for present roof bolting practices in India. From the hitherto known prior art it is clear that at present there is no such device available for manual roof bolting operation where cement capsule can be inserted into the drilled hole keeping aside the plastic/polybags. Thus, there is a definite need to provide such a device which will be able to send the cement as fast as possible which will give the required anchorage and capable of doing so by sending the cement without the polybag. The main objective of the present invention is to provide a device for improved manual grouting of roof bolts in mines, which will obviate the drawbacks of the hitherto known prior art. Another objective of the present invention is to provide a device for putting only water soaked grouting cement inside drilled hole in the roof of the mine keeping aside polybag during manual roof bolting operation, Still another objective of the present invention is to make the roof bolting system more reliable by keeping aside polybags inside the hole which is responsible for generations of voids in the grouting mixture. Yet another objective is to increase the anchorage strength of the roof bolts. A further objective of the present invention is to eliminate the churning operation which is required to tear the polybag and filling the annular space homogeneously. In the present invention there is provided a device for improved manual grouting of roof bolts in mines, which enables putting only water soaked grouting cement inside a drilled hole in the roof of the mine keeping aside poly-bag of the cement capsules during manual roof bolting operation. The cement containing polybag creates problem of not only covering the bolt to be grouted but also creates voids responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency. The invented device consists of two symmetrical semi circular pipes longitudinally hinged together at one edge and having locking pin at the other edge to form an openable cylindrical pipe. Both the symmetrical longitudinal halves of the openable cylindrical pipe having diamond cut knurling inside the concave surface to enable provide a tight grip to polybag enclosed cement capsule to be pushed into a drilled hole in mine roof for grouting of roof bolt. At the upper end of the assembled pipe is provided an annular ring having sharp circumferential teeth capable of tearing and withholding the polybag of the cement capsule in the pipe itself. The openable cylindrical pipe is provided at the lower end with a plunger capable of pushing the polybag enclosed cement capsule inside a drilled hole in the mine roof. In the process the annular ring having sharp teeth tearing and keeping the polybag in the pipe itself and pushing the cement grouting mixture inside the drilled hole in the mine roof. Thereby avoiding the polybag from covering the bolt to be grouted and creating voids responsible for improper bonding between the bolt and cement and thus bringing about increased grouting efficiency. The device of the present invention for improved manual grouting of roof bolts in mines, capable of putting only water soaked grouting cement inside a drilled hole in the roof of the mine, withholding the poly-bag of the cement capsules during manual roof bolting operation, is depicted in figures 1 and 2 of the drawings accompanying this specification. Figure 1 represents a cutout of the device of the present invention for improved manual grouting of roof bolts in mines. The device of the present invention as shown in figure 1 consists of a cylindrical pipe (1) made-up of two symmetrical semi-circular longitudinal halves. The two symmetrical semi circular pipe halves being longitudinally hinged together at one edge and having locking pin (5) at the other edge to form an openable cylindrical pipe (1). At the upper end of the openable cylindrical pipe (1) is provided an annular ring (3) having sharp circumferential teeth capable of tearing and withholding the polybag of a cement capsule in the pipe itself. At the lower end of the openable cylindrical pipe (1) is provided a plunger (4) such as a piston having long piston rod, capable of pushing the polybag enclosed cement capsule inside a drilled hole in the mine roof. Both the symmetrical semi-circular longitudinal halves having diamond cut knurling (2) in the concave part as shown in figure 2 of the drawings. The diamond cut knurling inside the concave surface to enables provide a tight grip to polybag enclosed cement capsule to be pushed into a drilled hole in mine roof for grouting of roof bolt. Accordingly the present invention provides a device for improved manual grouting of roof bolts in mines, which comprises in combination a cylindrical pipe (1) made-up of two symmetrical semi-circular longitudinal halves having knurled (2) concave surfaces; an annular ring (3) having sharp circumferential teeth; a plunger (4) and a locking pin (5); characterized in that the said two symmetrical semi circular pipe halves having knurled (2) concave surfaces being longitudinally hinged together at one edge and provided with a locking pin (5) at the other edge to form an openable cylindrical pipe (1); the said openable cylindrical pipe (1) being provided at the upper end with an annular ring (3) having sharp circumferential teeth and with a plunger (4) at the lower end. In an embodiment of the present invention, the inner diameter of the cylindrical pipe made-up of two symmetrical semi-circular longitudinal halves having knurled concave surfaces is equal to the diameter of the cement capsule to be used for grouting. In another embodiment of the present invention, the knurled concave surfaces being provided with diamond cut knurling. In still another embodiment of the present invention, the plunger is such as a piston having long piston rod at the lower end. A feature of the device of the present invention is that the two semi circular pipe halves having diamond cut knurling on the inside concave surface enables to grip the cement capsule packed in polybag. Another feature of the device of the present invention is that when the plunger fitted in the assembled pipe pushes the cement grouting mixture inside the drilled hole the annular ring having circumferential sharp teeth keeps back the polybag in the pipe itself and allows only grouting mixture to pass through it into the drilled hole. The working principle of the device of the present invention for improved manual grouting of roof bolts in mines, is very simple. First of all cement capsule consisting of cement in perforated polybag is properly soaked in water and placed inside the openable cylindrical pipe (1) below the annular ring (3) with circumferential sharp teeth. Then the two halves of the cylindrical pipe are locked through lock pin (5) such that the ploybag cement capsule is tightly held inside the cylinder by the diamond cut knurled (2) concave inside surface. After that the top part of the cylinder (1) is put inside the pre-drilled hole in the mine roof. Then by means of the piston (4) the soaked ploybag cement capsule is pushed upwards. As a result the polybag of the cement capsule comes in contact with the circumferential sharp teeth of the annular ring (3) and tears. Since the capsule is held tightly inside the cylindrical pipe (1) against the diamond cut knurling (2), the plastic of the capsule is held back by the diamond cut knurling (2) and the sharp teeth of the ring (3), while cement grouting is pushed upwards. After pushing the cement inside the drilled hole, the cylinder (1) is taken out and plastic polybag cover is removed by opening the two parts of the openable cylinder (1) by removing the lock pin (5). The novelty of the present invention resides in providing a simple almost maintenance free device for improved manual grouting of roof bolts in mines, wherein by withholding the polybag of the grouting cement capsule inside the device itself generation of voids is eliminated and grouting efficiency is increased in mine roof bolting. Thus making the roof bolting system more reliable with enhancement of anchorage strength and thus filling the annular space homogeneously which is responsible for generations of voids in the grouting mixture. The novelty of the present invention is realized by the device of the present invention having a combination of non obvious inventive constructional features such as an openable cylindrical pipe made up of two symmetrical semi-circular parts having diamond cut knurling in the concave inner surface, an annular ring having circumferential sharp teeth and a piston having long piston rod, and a lock pin for tightly locking the two longitudinal hinged halves of the cylindrical pipe. This enables to withhold the polybag of the cement capsule which is responsible for non-homogeneous filling of the annular space system and thus decreasing grouting efficiency. The following example is given to illustrate the working of the device of the present invention in actual practice and should not be construed to limit the present invention in any manner. Example: 1 A prototype of the device of the present invention was fabricated in mechanical workshop. The overall length being 60 cms and the circular cross section having inner diameter equal to the diameter of the cement capsule. A cement capsule consisting of cement in perforated polybag was properly soaked in water and placed inside the openable cylindrical pipe just below the annular ring with circumferential sharp teeth. Then the two halves of the cylindrical pipe were locked by means of the lock pin. After that the top part of the cylinder was put inside a pre-drilled hole in the mine roof. Then by means of the piston the soaked ploybag cement capsule was pushed upwards. As a result the polybag of the cement capsule came in contact with the circumferential sharp teeth of the annular ring and in the process the polybag was torn and remained in the pipe itself and only the cement grouting mixture was pushed inside the drilled hole in the mine roof. After pushing the grouting cement inside the drilled hole, the cylinder was taken out and the plastic polybag cover was removed by opening the two parts of the openable cylinder by removing the lock pin. Thus the device of the present invention for improved manual grouting of roof bolts in mines, is capable of putting only water soaked grouting cement inside drilled hole in the roof of the mine keeping aside poly-bag of the cement capsules during manual roof bolting operation. Hence, it is seen that by avoiding the polybag from covering the bolt to be grouted and creating voids responsible for improper bonding between the bolt and cement and thus bringing about increased grouting efficiency. The main advantages of the device of the present invention for improved manual grouting of roof bolts in mines are: 1. Very simple in design. 2. Ease of operation. 3. Maintenance is nil. 4. No special training is required for using it. 5. Prevents plastic to move inside the drilled hole along with the water soaked cement, which eliminates the problem of bondage between the cement and roof bolt due to wrapping of plastic throughout the bolt length and non-formation of voids, thus increasing bondage strength. 6. Increases the efficiency of grouting. We claim: 1. A device for improved manual grouting of roof bolts in mines, which comprises in combination a cylindrical pipe (1) made-up of two symmetrical semi-circular longitudinal halves having knurled (2) concave surfaces; an annular ring (3) having sharp circumferential teeth; a plunger (4) and a locking pin (5); characterized in that the said two symmetrical semi circular pipe halves having knurled (2) concave surfaces being longitudinally hinged together at one edge and provided with a locking pin (5) at the other edge to form an openable cylindrical pipe (1); the said openable cylindrical pipe (1) being provided at the upper end with an annular ring (3) having sharp circumferential teeth and with a plunger (4) at the lower end. 2. A device as claimed in claim 1, wherein the inner diameter of the cylindrical pipe made-up of two symmetrical semi-circular longitudinal halves having knurled concave surfaces is equal to the diameter of the cement capsule to be used for grouting. 3. A device as claimed in claim 1-2, wherein the knurled concave surfaces being provided with diamond cut knurling. 4. A device as claimed in claim 1-3, wherein the plunger is such as a piston having long piston rod at the lower end. 5. A device for improved manual grouting of roof bolts in mines, substantially as herein described with reference to the example and figures 1 & 2 of the drawings accompanying this specification.

Full Text

The present invention relates to a device for improved manual grouting of roof bolts in mines. The present invention particularly relates to a device for putting only water soaked grouting cement inside a drilled hole in the roof of the mine, withholding the poly-bag of the cement capsules during manual roof bolting operation. The present invention more particularly relates to a device which allows the grouting cement to be pushed into a drilled roof hole and withholds the cement containing polybag which creates problem of not only covering the bolt to be grouted but also creates voids responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency.
Roof bolting as a system of mine support is practiced in most of the coalfields in India. In most of the mines roof bolting is carried out manually using cement capsule cartridge. In the present hitherto known roof bolting system cement capsules followed by a roof bolt is inserted into a predetermined hole made by drilling machine in the mine roof. In the common practice for manual roof bolting, first of all hole is made in the mine roof using a drilling machine. Then water soaked cement capsule packed in perforated polybag is pushed in series into the hole with the help of a push rod, such as a wooden ranging rod. A tor steel roof bolt is inserted immediately thereafter into the hole, which punctures the cement packed polybag and thus fills the annular space between bolt and drilled hole with the cement along the full column. After the bolt is pushed into the hole, to make homogeneous filling of cement in annular space, the bolt is rotated to churn the cement and also to tear off the polybag of the cement capsules cartridge and thereby cement fills the annular space between the bolt and hole. But the cement containing polybag creates problem of not only covering the bolt but also creates voids which are responsible for improper bonding between the bolt and cement and thus
brings about decrease in the grouting efficiency. It has been observed that plastic often wraps up over the bolt during churning operation and thus prevents proper bondage between the bolt and the cement grout. This decreases the efficiency of the roof bolting by improper load transformation from the surrounding rock to the bolt through cement grout.
To overcome this difficulty roof bolting machine with separate pump was used for grouting the bolt by pumping cement slurry into the hole. But this method has inherent drawbacks, as follows:
a) Costly pump.
b) Wastage of cement slurry.
c) Improper time management.
d) Complicated operation.
e) Requirement of skilled worker.
On making a search of patent databases the following patent references come to light.
References may be made to US Patent No. 4126003, titled: Inorganic cement grouting system for use in anchoring a bolt in a hole; US Patent no.4126005, titled: Inorganic cement grouting system for use in anchoring a bolt in a hole and compartmented package for use therewith and US Patent no.4126009, titled: Inorganic cement grouting system for use in anchoring a bolt in a hole, wherein is disclosed an apparatus and a method in which two separate components of an inorganic cement grouting cement are mixed and delivered into the hole separately i.e. from separate feeding conduits or more preferably in separate compartment of a frangible package which is broken by the penetration and rotation of the reinforcing member.
Reference may also be made to US Patent no. 411638, titled: Clog-free inorganic grout emplacement gun wherein is disclosed an apparatus in which a emplacement gun particularly adopted for use in coal or similar mines for retaining roof bolts in bore holes. Four numbers of separate paths have been made into the hole for conveying the different mixing materials.
Reference may be drawn to US Patent no. 4079592, titled : Method of and apparatus for feeding and inserting bolts in a mine roof wherein is disclosed an apparatus and a method about installing resin anchored roof bolts in mine roof with the help of mobile roof bolter frame. In an apparatus for installing resin anchored roof bolts in a mine roof, continuous bolt material is stored on a spool rotatably mounted on a mobile roof bolter frame. As the apparatus advances along the mine passageway, the bolt material is uncoiled from the spool and guided upwardly into spaced apart, resin filled holes that are preformed in the mine roof. The bolt material is severed just beneath the roof at each hole to form a unitary roof bolt. A stop is formed in the unitary bolt with a hydraulically operated head and mandrel mechanism that makes a right angle bend in the bolt just beneath the mine roof.
Reference may be taken from the US Patent no. 4643619, titled : Apparatus for feeding cement material into a drill hole for cement bolting of a rock, wherein is disclosed an apparatus and a method of feeding cement into a drill hole for cement bolting of a rock in which a feeder pipe is pushed into the hole portion to be filled with cements. Cement is fed into the hole beginning from the bottom of the hole portion and the pipe is displaced outward in the hole when the cement fills the hole. Finally, feeding of cement stopped and the pipe is removed and then rock bolt is pushed into the pipe.
Reference may also be taken from the US Patent no.6793445, titled : Method and apparatus for insertion of rock bolts wherein is disclosed an internal cavity into the rock bolt having an injection assembly to retain the grouting compound. When the rock bolt is inserted in the member and when the injection assembly engages the member the passage is in communication with the internal cavity in the rock bolt. Whereupon the injection assembly operates to inject a predetermined quantity of the grouting compound into a bolt hole in the rock strata via the internal cavity of the bolt.
Reference may also be drawn from the US Patent no.6033153, titled : Rock bolt and method of installing a rock bolt wherein is disclosed an apparatus and a method of installing a rock bolt .particularly a hollow bolt. The method of installation utilizes a chemical anchor in form of a cartridge.
Reference may also be made to US Patent no.5494380, titled : Resin injector system, wherein is disclosed an apparatus and a method which employs gas to position a resin sausage into a bolt hole drilled by a rock bolter. The invention relates to a system and a method which employs gas to position a resin sausage into a bolt hole drilled by a rock bolter. The system provides a controlled quantity of liquid into a resin sausage insertion chamber prior to supplying the gas to eject the sausage from the resin sausage insertion chamber. The liquid enhances the reliability and accuracy of the placement of the sausages in the bolt hole. Preferably, the system includes an expansion chamber through which the gas passes. The expansion chamber is provided so that the gas can be partially displaced by liquid and thereafter, liquid will be advanced into the resin sausage insertion chamber prior to the gas. The system can either have its own fluid supply or alternatively use a fluid supply of the rock bolter if one is provided for flushing the bolt holes. In
either case, it is preferred that the expansion chamber is adjustable so as to allow the volume of liquid and gas to be adjusted for the operating conditions of the rock bolter.
From the above, it is observed that in the hitherto known prior art there are various types of methods and devices available which use separate conduit pipes, feeders pipes and in some cases internal cavity was made in the rock bolts itself to send the inorganic cement slurry. In some device resins and other chemicals were used for anchoring. From the hitherto known prior art it is also seen that none have disclosed any method or device about the manual grouting of roof bolts in mines using cement capsuling i.e cement packed in polybag in form of capsule and the problems of anchoring thereof.
From the hitherto known prior art it is obvious that the devices and methods which are mentioned herein above are costly as well as complicated in design and may not be suitable for present roof bolting practices in India. From the hitherto known prior art it is clear that at present there is no such device available for manual roof bolting operation where cement capsule can be inserted into the drilled hole keeping aside the plastic/polybags. Thus, there is a definite need to provide such a device which will be able to send the cement as fast as possible which will give the required anchorage and capable of doing so by sending the cement without the polybag.
The main objective of the present invention is to provide a device for improved manual grouting of roof bolts in mines, which will obviate the drawbacks of the hitherto known prior art.
Another objective of the present invention is to provide a device for putting only water soaked grouting cement inside drilled hole in the roof of the mine keeping aside polybag during manual roof bolting operation,
Still another objective of the present invention is to make the roof bolting system more reliable by keeping aside polybags inside the hole which is responsible for generations of voids in the grouting mixture. Yet another objective is to increase the anchorage strength of the roof bolts.
A further objective of the present invention is to eliminate the churning operation which is required to tear the polybag and filling the annular space homogeneously.
In the present invention there is provided a device for improved manual grouting of roof bolts in mines, which enables putting only water soaked grouting cement inside a drilled hole in the roof of the mine keeping aside poly-bag of the cement capsules during manual roof bolting operation. The cement containing polybag creates problem of not only covering the bolt to be grouted but also creates voids responsible for improper bonding between the bolt and cement and thus brings about decrease in the grouting efficiency. The invented device consists of two symmetrical semi circular pipes longitudinally hinged together at one edge and having locking pin at the other edge to form an openable cylindrical pipe. Both the symmetrical longitudinal halves of the openable cylindrical pipe having diamond cut knurling inside the concave surface to enable provide a tight grip to polybag enclosed cement capsule to be pushed into a drilled hole in mine roof for grouting of roof bolt. At the upper end of the assembled pipe is provided an annular ring having sharp circumferential teeth capable of tearing and
withholding the polybag of the cement capsule in the pipe itself. The openable cylindrical pipe is provided at the lower end with a plunger capable of pushing the polybag enclosed cement capsule inside a drilled hole in the mine roof. In the process the annular ring having sharp teeth tearing and keeping the polybag in the pipe itself and pushing the cement grouting mixture inside the drilled hole in the mine roof. Thereby avoiding the polybag from covering the bolt to be grouted and creating voids responsible for improper bonding between the bolt and cement and thus bringing about increased grouting efficiency.
The device of the present invention for improved manual grouting of roof bolts in mines, capable of putting only water soaked grouting cement inside a drilled hole in the roof of the mine, withholding the poly-bag of the cement capsules during manual roof bolting operation, is depicted in figures 1 and 2 of the drawings accompanying this specification.
Figure 1 represents a cutout of the device of the present invention for improved manual grouting of roof bolts in mines. The device of the present invention as shown in figure 1 consists of a cylindrical pipe (1) made-up of two symmetrical semi-circular longitudinal halves. The two symmetrical semi circular pipe halves being longitudinally hinged together at one edge and having locking pin (5) at the other edge to form an openable cylindrical pipe (1). At the upper end of the openable cylindrical pipe (1) is provided an annular ring (3) having sharp circumferential teeth capable of tearing and withholding the polybag of a cement capsule in the pipe itself. At the lower end of the openable cylindrical pipe (1) is provided a plunger (4) such as a piston having long piston rod, capable of pushing the polybag enclosed cement capsule inside a drilled hole in the mine roof. Both the symmetrical

semi-circular longitudinal halves having diamond cut knurling (2) in the concave part as shown in figure 2 of the drawings. The diamond cut knurling inside the concave surface to enables provide a tight grip to polybag enclosed cement capsule to be pushed into a drilled hole in mine roof for grouting of roof bolt.
Accordingly the present invention provides a device for improved manual grouting of roof bolts in mines, which comprises in combination a cylindrical pipe (1) made-up of two symmetrical semi-circular longitudinal halves having knurled (2) concave surfaces; an annular ring (3) having sharp circumferential teeth; a plunger (4) and a locking pin (5); characterized in that the said two symmetrical semi circular pipe halves having knurled (2) concave surfaces being longitudinally hinged together at one edge and provided with a locking pin (5) at the other edge to form an openable cylindrical pipe (1); the said openable cylindrical pipe (1) being provided at the upper end with an annular ring (3) having sharp circumferential teeth and with a plunger (4) at the lower end.
In an embodiment of the present invention, the inner diameter of the cylindrical pipe made-up of two symmetrical semi-circular longitudinal halves having knurled concave surfaces is equal to the diameter of the cement capsule to be used for grouting.
In another embodiment of the present invention, the knurled concave surfaces being provided with diamond cut knurling.
In still another embodiment of the present invention, the plunger is such as a piston having long piston rod at the lower end.
A feature of the device of the present invention is that the two semi circular pipe halves having diamond cut knurling on the inside concave surface enables to grip the cement capsule packed in polybag.
Another feature of the device of the present invention is that when the plunger fitted in the assembled pipe pushes the cement grouting mixture inside the drilled hole the annular ring having circumferential sharp teeth keeps back the polybag in the pipe itself and allows only grouting mixture to pass through it into the drilled hole.
The working principle of the device of the present invention for improved manual grouting of roof bolts in mines, is very simple. First of all cement capsule consisting of cement in perforated polybag is properly soaked in water and placed inside the openable cylindrical pipe (1) below the annular ring (3) with circumferential sharp teeth. Then the two halves of the cylindrical pipe are locked through lock pin (5) such that the ploybag cement capsule is tightly held inside the cylinder by the diamond cut knurled (2) concave inside surface. After that the top part of the cylinder (1) is put inside the pre-drilled hole in the mine roof. Then by means of the piston (4) the soaked ploybag cement capsule is pushed upwards. As a result the polybag of the cement capsule comes in contact with the circumferential sharp teeth of the annular ring (3) and tears. Since the capsule is held tightly inside the cylindrical pipe (1) against the diamond cut knurling (2), the plastic of the capsule is held back by the diamond cut knurling (2) and the sharp teeth of the ring (3), while cement grouting is pushed upwards. After pushing the cement inside the drilled hole, the cylinder (1) is taken out and plastic polybag cover is removed by opening the two parts of the openable cylinder (1) by removing the lock pin (5).
The novelty of the present invention resides in providing a simple almost maintenance free device for improved manual grouting of roof bolts in mines, wherein by withholding the polybag of the grouting cement capsule inside the device itself generation of voids is eliminated and grouting efficiency is increased in mine roof bolting. Thus making the roof bolting system more reliable with enhancement of anchorage strength and thus filling the annular space homogeneously which is responsible for generations of voids in the grouting mixture.
The novelty of the present invention is realized by the device of the present invention having a combination of non obvious inventive constructional features such as an openable cylindrical pipe made up of two symmetrical semi-circular parts having diamond cut knurling in the concave inner surface, an annular ring having circumferential sharp teeth and a piston having long piston rod, and a lock pin for tightly locking the two longitudinal hinged halves of the cylindrical pipe. This enables to withhold the polybag of the cement capsule which is responsible for non-homogeneous filling of the annular space system and thus decreasing grouting efficiency.
The following example is given to illustrate the working of the device of the present invention in actual practice and should not be construed to limit the present invention in any manner.
Example: 1
A prototype of the device of the present invention was fabricated in mechanical workshop. The overall length being 60 cms and the circular cross section having inner diameter equal to the diameter of the cement capsule. A
cement capsule consisting of cement in perforated polybag was properly soaked in water and placed inside the openable cylindrical pipe just below the annular ring with circumferential sharp teeth. Then the two halves of the cylindrical pipe were locked by means of the lock pin. After that the top part of the cylinder was put inside a pre-drilled hole in the mine roof. Then by means of the piston the soaked ploybag cement capsule was pushed upwards. As a result the polybag of the cement capsule came in contact with the circumferential sharp teeth of the annular ring and in the process the polybag was torn and remained in the pipe itself and only the cement grouting mixture was pushed inside the drilled hole in the mine roof. After pushing the grouting cement inside the drilled hole, the cylinder was taken out and the plastic polybag cover was removed by opening the two parts of the openable cylinder by removing the lock pin.
Thus the device of the present invention for improved manual grouting of roof bolts in mines, is capable of putting only water soaked grouting cement inside drilled hole in the roof of the mine keeping aside poly-bag of the cement capsules during manual roof bolting operation. Hence, it is seen that by avoiding the polybag from covering the bolt to be grouted and creating voids responsible for improper bonding between the bolt and cement and thus bringing about increased grouting efficiency.
The main advantages of the device of the present invention for improved manual grouting of roof bolts in mines are:
1. Very simple in design.
2. Ease of operation.
3. Maintenance is nil.
4. No special training is required for using it.
5. Prevents plastic to move inside the drilled hole along with the water
soaked cement, which eliminates the problem of bondage between the
cement and roof bolt due to wrapping of plastic throughout the bolt length
and non-formation of voids, thus increasing bondage strength.
6. Increases the efficiency of grouting.

We claim:
1. A device for improved manual grouting of roof bolts in mines, which
comprises in combination a cylindrical pipe (1) made-up of two symmetrical
semi-circular longitudinal halves having knurled (2) concave surfaces; an
annular ring (3) having sharp circumferential teeth; a plunger (4) and a
locking pin (5); characterized in that the said two symmetrical semi circular
pipe halves having knurled (2) concave surfaces being longitudinally hinged
together at one edge and provided with a locking pin (5) at the other edge to
form an openable cylindrical pipe (1); the said openable cylindrical pipe (1)
being provided at the upper end with an annular ring (3) having sharp
circumferential teeth and with a plunger (4) at the lower end.
2. A device as claimed in claim 1, wherein the inner diameter of the
cylindrical pipe made-up of two symmetrical semi-circular longitudinal halves
having knurled concave surfaces is equal to the diameter of the cement
capsule to be used for grouting.
3. A device as claimed in claim 1-2, wherein the knurled concave surfaces
being provided with diamond cut knurling.
4. A device as claimed in claim 1-3, wherein the plunger is such as a piston
having long piston rod at the lower end.
5. A device for improved manual grouting of roof bolts in mines, substantially as herein described with reference to the example and figures 1 & 2 of the drawings accompanying this specification.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=vSxa2GssmeRcufdkRf2ATg==&loc=+mN2fYxnTC4l0fUd8W4CAA==

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Patent Number

271486

Indian Patent Application Number

2584/DEL/2006

PG Journal Number

09/2016

Publication Date

26-Feb-2016

Grant Date

23-Feb-2016

Date of Filing

04-Dec-2006

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

ANUSANDHAN BHAWAN, RAFI MARG,NEW DELHI-110001,INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	KASHYAP SUDHIR KUMAR	CENTRAL MINING RESEARCH INSTITUTE,DHANBAD
2	TEWARI SUBHASHISH	CENTRAL MINING RESEARCH INSTITUTE,DHANBAD
3	SINHA AMALENDU	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD

PCT International Classification Number

E21D21/00; E21D20/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA